Typewriter case shift mechanism



Feb. 22, 1955 H. P. LUHN TYPEWRITER CASE SHIFT MECHANISM 5 Shfaiats- Sheefiv l Original Filed Dec. 9. 1950 JNVENTOR. A64/V5 P UH/V A 7' TURA/EY Feb. 22, 1955 H. P. LUHN TYPEWRITER CASE SHIFT Mr-:cHANIsM 5 Sheets-Sheet 2 original Filed Dec. 9. 195o JN V EN TOR.

. ATTORNEY Feb. 22, 1955 2,702,621

H. P. LUHN TYPEWRITER CASE SHIFT MECHANISM Original Filed Dec. 9, 1950 5 Sheets-Sheet 3 W4 TTI Vl QQ 9 Q n ATTORNEY Feb. 22, 1955 H. P. I UHN 2,702,621.

TYPEWRITER CASE SHIFT MECHANISM original Filed Dec. 9. 195o 5 sheets-sheat-4 INVENTOR. HANS .P L l/H/V Feb. 22, 1955 H. P. I UHN TYPEWRITER CASE SHIFT MECHANISM Original Filed Dec. 9, 1950 TYPEWRITER CASE SHIFT MECHANISM Hans Lulin, Armonk, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York @riginal application December 9, 1950, i Serial No. 199,989. Divided and this application December 31, 1951, Serial No. 264,329

6 Claims. (Cl. 197-81) This invention relates in general to a typewriter case shifting mechanism and in particular to mechanism for effecting the shitting of a typewriter basket from a lower to either an upper case or partial case position.

This application is a division of the copending applicagio19o5t`0l-lans P. Luhn, Serial No. 199,989, filed December The principal object of the invention is to provide a basket shifting mechanism for enabling a typewriter basket to assume one of three possible positions.

Another object of the invention is to provide key controlled interposer means for stopping a typewriter basket intermediate the lower and upper case positions.

A further object of the invention is to provide a partial shift key controlled means for modifying the action of a shift key so as to prevent a typewriter basket from making a t'ull shift from a lower to an upper case position.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of examples, the principle ot' the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a plan view of a power driven typewriter.

Fig. 2 is a transverse vertical section view through the typewriter, the section being taken on the section line 2 2 of Fig. 1.

Fig. 3 is a fragmentary vertical section showing the details of the shift lock key and the related linkage arrangement for effecting the shifting of the typewriter basket from a lower to an upper case position.

Fig. 4 is an isometric view, partly cut away, to show the details of the mechanical arrangement existing between the partial shift key, the shift release key, and the shift lock key.

Fig. 5 is a view partly cut away and partly in section showing the details of the partial shift key lever and the associated key lever for effecting the shifting of the typewriter basket from a lower to a partial case position.

Figs. 6a to 6d are a diagrammatic showing of the position of the type slugs necessary to' effect the printing gf certain selected characters in subscript or superscript crm.

There is shown in Fig. 1 a well known commercial form of power driven typewriter 200, the operating principles and structural features of such typewriter being fully disclosed in a number of U. S. patents including Patents No. 1,777,055 granted September 30, 1930, and No. 1,873,512 granted August 23, 1932.

As shown in Figs. 1 and 2, the typewriter 200 comprises a laterally movablelcarriage 201 on which is mounted the usual platen 202 for supporting a copy sheet 203 in printing position. The type bars 204 are pivotally mounted in a type basket 205 and each type bar carries a lower case type element 206a and an upper case element 206b.

Inasmuch as the intended operation of the typewriter calls for the printing of subscripts and superscripts, thus necessitating the use of three shift positions of the type basket, the mechanism for effecting the same being described subsequently, it is necessary that the upper and lower case type embossments in the selected type slugs be closer together than usual such as shown in Figs. 6a and 6b where the slug of Fig. 6a shows the normal nitcd States Patent O 2,702,621 Patented Feb. 22, 1955 character spacing, while the slug of Fig. 6b shows the modified spacing arrangement. the modified "l" type slug or Fig. 6b has a lower case "l" and an upper case "l" such that when the type basket is 1n the lower case position, the lower case l will be positioned on the printing line as shown in rig. ob wnen printing occurs. When the shift key 235 or the shirt lock key 216 (Fig. 4) is depressed, the type basket will be lowered so that me upper case l will print as a subscript as shown in big. oc. When the partial shift key 2l: is depressed, the type basket is only permitted to make a partial shirt instead of' a full shirt, as shall be seen subsequently, resulting in the upper case l being printed as a superscript character as shown in Fig. 6a.

'l'ne type basket 205 normally occupies its lower case position where, when a type bar is actuated, the lower case element 206a is printed on the sheet 203. ln a manner well understood by those skilled in this art, the basket 205 may be shifted to its upper case position and in such position an actuated type bar will ettect printing of its upper case character 2U6b. Likewise, the basket 205 may be shifted to a third position which is intermediate the upper and lower case positions and which shall be hereinafter referred to as the partial shift position.

The typewriter 200 also comprises a keyboard 210 including the usual complement of character and functional keys. The character keys are indicated by the numeral 211, the carriage return key by 212, the tabulating key by 213, the bar 214 is the space key, the key 215 is the partial shift key, the key 216 is the shift lock key, the key 217 the shift release key, and the key 235 is the shift key. Each key is mounted on a key lever 220 and when depressed effects the printing of the corresponding character or functional operation in a manner which is either known to those skilled in this art, or which shall be described subsequently.

Briefly, referring to Fig. 2, depression of a character key 211 effects operation of a cam unit 221 by releasing a latch 222 from a cam 223, thereby permitting a springpressed lever 224 to move the cam against the periphery of a continuously rotating motor-driven shaft 225. The cam is rotated by frictional contact with shaft 225 causing the carrier 226 of the cam to rock in a direction for pulling a link 227 which, through a suitable linkand-lever arrangement, propels a corresponding type bar 204 toward the platen 202 to effect printing of the character denoted on the operated character key. During the final increment of movement of the type bar 204, it strikes a universal bar 228 to actuate through suitable linkage an escapement lever 229 for releasing the escapement mechanism and thereby effecting a carriage spacing movement.

Depression of the space bar 214 similarly results in downward movement of a key lever 220 to effect operation of a cam unit 223 and thereby operate suitable linkage for actuating the escapement lever 229 to cause a character or letter space operation not disclosed in detail herein, but fully disclosed in the above mentioned U. S. Patent No. 1,873,512.

The carriage return mechanism operated by depressing the key 212 is of the type disclosed in U. S. Patents No. 2,104,559 granted January 4, 1938, and No. 1,753,450 granted April 8, 1930. As is usual, the carriage return movement is accompanied by a line spacing operation effected as an incident thereto, a repeated depression of the carriage return key merely causing an additional line space operation.

The tabulating mechanism operated by key 213 is such as shown in U. S. Patent No. 1,935,436 granted November 14, 1933, and includes the usual settable tabular stops 230 mounted on a rack bar 231 extending across the back of the machine (Fig. 2). As is disclosed fully in the last mentioned patent, the depressing of the tab key effects movement of a tab lever (not shown) to an operated position and thereby releases the escapement mechanism to permit movement of the carriage 201. When the carriage 201 reaches the character space position where a regular tab stop 230 has been preset, the tab lever is engaged by the preset stop and ICC thereby stops the carriage and restores the tab lever to normal position at such character space position.

Depression of the shift lock key 216 (Fig. 4), either manually or through the energization of the associated solenoid 240-Shift Lock, eifects a basket shift operation which moves the type basket 205 from its normal or lower case position to its upper case position. The shift lock key 216 is pivotally mounted at 170 (Fig. 4) on the key lever 220 of the shift key 235 and when depressed, is retained in an operating position by a suitable latch 171 catching under a hook 172 fixed to the typewriter frame such as fully disclosed in a number of patents, including No. 2,378,371 granted June l2, 1945. As explained in the latter patent, the shift lock key 216 is released by depressing the shift release key 217 (Fig. 4), which operation effects through bail lever 173 (Fig. 4) a downward movement of the key lever 220 on which the shift lock key 216 is pivotally mounted at 170. The latter movement causes the usual spring 174l to release the latch 171 which holds down the shift lock key. Thus, when the shift release key 217 is released, key lever 220 associated with the shift lock key 216 is then permitted to move upward to its normal position and in so doing to effect the return of the type basket to its normal or lower case position.

While either the shift key 235 or the shift lock key 216, may, upon being manually depressed, also effect the shifting of the basket from normal to upper case position, the shift lock key 216 through the shift lock solenoid 240 is used exclusively to shift and lock the basket in an upper case position, thus obviating the unwanted operation of pulsing the solenoid each cycle for a continuous series of upper case characters.

Depression of the partial shift key 215 (Fig. 4), either manually or through the energization of the partial shift solenoid 240, effects a basket shift operation which moves the type basket 205 from its normal or lower case position to a partial shift position.

When the partial shift key 215 and its associated key lever 220 are depressed, the key lever 220 pivots counterclockwise about its supporting shaft 176 (Fig. 4) pivotally supported near each end thereof by the supporting members 199, thereby causing the shaft to turn in a counterclockwise direction. There is secured to the shaft 176, at each end thereof, a pair of spaced actuating elements 218 which, with the movement of the shaft 176 in a counterclockwise direction, are also moved in a counterclockwise direction against the studs 177 secured to the spring biased interposers 17S (Fig. 3) thereby causing the interposers 178 to be rocked about the respective pivots 179 to the dotted line position as shown in Fig. 3. It is to be noted that the supporting members 199 in addition to pivotally supporting the shaft 176 also pivotally support the interposers 17S at the pivots 179.

As the partial shift key 215 and its associated key lever 220 are being depressed, the shift release key 217 is also depressed through the medium of the partial shift lock lever 180 (Figs. 4 and 5). Partial shift lock lever 180 is pivotally mounted on the stud 181 secured to the key lever associated with the partial shift key 215. Partial shift lock lever 180 has integral therewith an ear 182, a slotted arm 133 and a latch 184. The key lever 220 which is associated with the partial shift key 215 is resting on the ear 182 as shown in Fig. 4, while the slotted arm 183 is operatively associated with the stud extension 185 of the plate 186 of the bail lever 173. The bail lever 173 comprises a pair of end plates 186 and 187 (Fig. 4) connected by a bail rod 189. Bail lever 173 is mounted for pivotal movement by the studs 190 and 191 (Fig. 4) extending outwardly from the plates 186 and 187 and secured respectively within opposite sides of typewriter frame not shown. The stud 185 extends inwardly from the end plate 186 and within a notch 192 (Fig. 4) formed in the downwardly extending projection of the key lever 220 associated with the shift release key 217. A second stud 193 extends inwardly from the plate 187 and over the hook 194 associated with the shift key lever 220.

Thus, when the partial shift key 215 is depressed the stud extension 135 of the bail lever 173 is rocked countercockwise. as viewed in Fig. 4, about the supporting studs 190 and 191 through the cooperative action of the slotted arm 133 upon the stud 185. Also when the partial shift key 215 is depressed, the latch 184 will be hooked under the member 195, thereby retaining the partial shift key lever 220 in a depressed position. Likewise, when the stud is rocked counterclockwise, the notch 192 meshing with the stud 185 will through the functioning of the bail lever 17 3 cause the shift key lever 220 to be depressed, thereby releasing the associated shift carn 221 (Fig. 3) to lower the type basket 205 from the lower to the upper case position. However, the type basket will be prevented from making a full shift because the stop 196 (Fig. 5) will encounter the interposer 178 which has assumed the dotted line position, as previously explained. In order to release the partial shift key lever 220 for return to its normal position and to return the basket to its lower position, it is necessary that the shift release key 217 be further depressed either manually or through the energization of the associated solenoid. As the shift release key lever 220 is depressed, the notch 192 integral therewith and meshing with the stud 185 causes the stud 185 to be rocked in a counterclockwise fashion as viewed in Fig. 4. Since the slotted arm 183 of the partial shift lock lever 180 also meshes with the stud 185, the movement of the latter element will cause the partial shift lock lever 180 to be rocked clockwise around its pivot stud 181, thereby releasing the latch 134 from engagement with the member and as a result, permitting the partial shift key lever 220 to return to its normal position.

According to the present invention, three pairs of type basket contacts 234 (Fig. 5), and 236 and 237 (Fig. 2) are provided. The contacts 236 and 237 (Fig. 2) are of the transfer type and are actuated by an arm 238 xed to an operating shaft 239 of the basket shift mechanism. The shaft 239 occupies its normal position shown when the type basket 205 is in its lower case position. In this position the contacts 236 are closed and the contacts 237 open. When the type basket is shifted to its upper case position, the shaft 239 is rocked counterclockwise as an incident to the shifting operation and, through the arm 238, opens contacts 236 and closes contacts 237. When the type basket is returned to lower case position, the contacts 236 are again closed and the contacts 237 opened, as will be apparent.

The contacts 234 (Fig. 5) secured to the frame of the typewriter are actuated by the lever arm 197 operably associated with the shouldered portion 198 of the partial shift key lever 220. When the partial shift key lever 220 is in its normal position, the arm 197 resting on the shoulder 198 prevents the contacts 234 from being closed. When the partial shift key lever 220 is depressed, the shouldered portion 193 of the lever drops followed by the lever arm 197, thereby removing the restraining effect upon the contacts 234 and resulting in the contacts 234 being engaged. When the basket is being shifted to partial case position, the shaft 239 (Fig. 2) is turned counterclockwise a distance sufficient to place the contacts 236 and 237 in an open position. Thus, it is to be noted that when the contacts 234 are closed, the contacts 236 and 237 are open.

Supplementing the above construction and peculiar to the present invention, are a plurality of typewriter actuating solenoids 240, there being an actuating solenoid for the space bar and an actuating solenoid for each of the various other keys of the keyboard that are required to be operated. As shown in Fig. 4, the armature of each solenoid 240 is connected to its correspondingly key lever 220. Thus, energization of a solenoid results in automatic operation of its related key and the mechanism operated by such key.

As shown in Fig. 2, a special rack bar 250 is mounted on the carriage 201 for movement therewith, and is fixed at its two ends to rearwardly extending support plates 251 and 252 (Fig. l), respectively, which are suitably fixed to the two end plates of the carriage 201. As shown, the special rack bar 250 is formed with a plurality of pairs of vertical grooves 253, 253, the grooves forming each pair being formed on opposite sides, respectively, of the bar 250 and extending in a common vertical plane. The several pairs of grooves 253, 253 correspond, respectively, to the characterspace positions of the carriage. Each of the pairs of grooves is adapted to receive a stop 257. The control stop 257 functions when the carriage 201 reaches the character-space position corresponding to the pairs of grooves where such control stop has been placed, to open, or close, a related pair of contacts not shown mounted within a contact assembly 258 fixed to the rear portions of the typewriter frame.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a case shift mechanism for typewriting machines, a plurality of spaced case shifting keys, means operably coupling said keys, a case shiftable unit, means operably associated with said unit and controlled by said keys including associated power operating devices and linkage arrangements for shifting said unit from a lower case to an upper case position, and key control means for shifting said unit to a position intermediate said lower and upper case positions including actuating means controlled by said key control means, interposer means operably associated with said actuating means, and means normally coupled with said key coupling means, said key control means upon being actuated operating upon said key coupling means to shift said unit from a lower toward an upper case position, said key control means at the same time operating upon said actuating means to move said interposer means into a position to prevent said unit from assuming the upper case position, said interposer means enabling said unit to be halted at a position intermediate said lower and upper case positions.

2. In a typewriting machine, the combination of a frame, a platen, a type basket, a plurality of type bars mounted in said basket and individually movable into engagement with said platen, means for shiftably supporting said basket on said frame, upper and lower case types mounted on certain ones of said type bars, a plurality of types on the remaining ones of said type bars being spaced closer to each other than said upper and lower case types, a first key control means including lever means for shifting said basket from a lower to an upper case position, and a second key control means for shifting said basket from a lower position to a position intermediate said upper and lower case positions, said second means including key lever means, actuating means controlled thereby, interposer means operably associated with said actuating means, a pivotable latching means, and means operably coupling said latching means with said first key control means, said key lever means upon being actuated operating upon said first key control means through said latching means causing said basket to shift from lower toward upper case position, said key lever means also upon being actuated rocking said actuating means causing said interposer means to be moved in a direction to prevent said basket from shifting to the upper case position, said interposer means stopping said basket at a position intermediate said lower and upper case positions.

3. A case shift mechanism for typewriting machines comprising a case shiftable unit, a first key control means including power means for shifting said unit from a first to a second position, and a second key control means for shifting said unit to a position intermediate said first and second case positions, said second means including key lever means, actuating means controlled thereby, interposer means operably associated with said actuating means, a pivotable latching means, and means operably coupling said latching means with said first key control means, said key lever means upon being actuated operating upon said first key control means through said latching means, causing said unit to shift from said first toward said second position, said key lever means also upon being actuated rocking said actuating means, causing said interposer means to be moved in a direction to prevent said unit from shifting to the second position, said interposer means stopping said unit at a position intermediate said first and second positions.

4. In a case shift mechanism, means movable between three case shift positions, a first key control means including power means for shifting said movable means from a first to a second position, a second key control means, shaft means pivotably supporting said second key control means, a pair of spaced actuating elements secured to the ends of said shaft means, and spring biased interposer means operably associated with each of said elements, said second key control means operably associated with said first key control means for modif ing the action of said first key control means, said second means upon being actuated causing said movable means through said first means to shift from said first toward said second position, said second means at the same time effecting movement of said elements to cause the associated interposer means to be brought into the path of said movable means moving from said first toward said second position whereby each of said interposer means prevents said movable means from assuming said second position, said interposer means stopping said movable means at a third position.

5. Apparatus of the type described comprising a partial shift key means, key lever means associated therewith, a shift release key means, a partial shift lock lever means pivotably secured to said partial shift key means, said partial shift lock lever means including an ear, a slotted arm means and a latch means, said partial shift key lever means resting on said ear, bail rod means, pivotably supported bail lever means comprising a pair of end plates connected by said bail rod means, and stud means secured to one of said end plates, said shift release key means including a slotted projection means, said stud means operably associated with said slotted arm means and said slotted projection means, said partial shift key means upon being actuated through said slotted arm means causing said bail lever means to be rocked in a counterclockwise direction, said bail lever means moving in a counterclockwise direction causing said shift release key means likewise to be actuated.

6. Apparatus of the type described comprising a partial shift key means, key lever means associated therewith, a shift release key means, a partial shift lock 1ever means pivotably secured to said partial shift key means, said partial shift lock lever means including an ear, a slotted arm means and a latch means, said partial shift key lever means resting on said ear, bail rod means, pivotably supported bail lever means comprising a pair of end plates connected by said bail rod means, and stud means secured to one of said end plates, said shift release key means including a slotted projection means, said stud means operably associated with said slotted arm means and said slotted projection means, said partial shift key means upon being actuated moving said ear in a downward direction causing said slotted arm means to be moved in a counterclockwise direction, said slotted arm means in turn causing sato bail lever means to be rocked in a counterclockwise direction, said bail lever means moving in a counterclockwise direction causing said shift release key means likewise to be actuated.

Wasmuth Apr. 26, 1904 Hart Oct. 3, 1933 

